stl/CMakeLists.txt: Rerunning CMake relinks msvcp140_atomic_wait_oss.dll unnecessarily

[StephanTLavavej]

msvcp140_atomic_wait_oss.dll depends on a generated file:

STL/stl/CMakeLists.txt

Lines 505 to 513 in 4bb41db

	# generate the .def for msvcp140_atomic_wait.dll
	set(_ATOMIC_WAIT_OUTPUT_NAME "msvcp140${D_SUFFIX}_atomic_wait${VCLIBS_SUFFIX}")
	string(TOUPPER "${_ATOMIC_WAIT_OUTPUT_NAME}" _ATOMIC_WAIT_OUTPUT_NAME_UPPER)
	set(_ATOMIC_WAIT_DEF_NAME "${CMAKE_BINARY_DIR}/msvcp_atomic_wait${D_SUFFIX}.def")
	set(_ATOMIC_WAIT_DEF_FILE_SRC "${CMAKE_CURRENT_LIST_DIR}/src/msvcp_atomic_wait.src")
	set_property(DIRECTORY APPEND PROPERTY CMAKE_CONFIGURE_DEPENDS "${_ATOMIC_WAIT_DEF_FILE_SRC}")
	file(READ "${_ATOMIC_WAIT_DEF_FILE_SRC}" _ATOMIC_WAIT_SRC_CONTENTS)
	string(REPLACE "LIBRARYNAME" "${_ATOMIC_WAIT_OUTPUT_NAME_UPPER}" _ATOMIC_WAIT_DEF_CONTENTS "${_ATOMIC_WAIT_SRC_CONTENTS}")
	file(WRITE "${_ATOMIC_WAIT_DEF_NAME}" "${_ATOMIC_WAIT_DEF_CONTENTS}")

We're replacing this text:

STL/stl/src/msvcp_atomic_wait.src

Line 6 in 4bb41db

LIBRARY LIBRARYNAME

After building, rerunning ninja alone is fine:

D:\GitHub\STL>cmake -G Ninja -S . -B out\build\x64 && ninja -C out\build\x64
[...]
[977/977] Linking CXX static library out\lib\amd64\libcpmtd.lib

D:\GitHub\STL>ninja -C out\build\x64
ninja: Entering directory `out\build\x64'
ninja: no work to do.

However, rerunning cmake followed by ninja performs an unnecessary relink:

D:\GitHub\STL>cmake -G Ninja -S . -B out\build\x64 && ninja -C out\build\x64
[...]
[2/2] Linking CXX shared library out\bin\amd64\msvcp140_atomic_wait_oss.dll

@cbezault says that add_custom_command might be the cleanest way to do this.

We should avoid changing the content of msvcp_atomic_wait.src as the internal build system also needs to consume this file (and changing that is a headache).

[AlexGuteniev]

Maybe give up on that and go to __declspec(dllexport) ?